Answer
Moments went by and Sei was at the edge of his intense desire to just hugged her tight. Well, it was because he knew that it's still too early for him to rejoice.
He knew that what he had revealed were words that no one could just accept so easily. And they were words that was so difficult for him to say. Because, in his entire life, Sei never bothered explaining himself to anyone else. He didn't care no matter what people thinks about him. He hated the idea of trying to reason out for yourself just for someone to understand. That was why, he grew up being dependent on Zaki's social skills and he didn't really know how to explain himself the better way.